Tipping torch for exhaust machines



Nov. 1,1927

H. DE F. MADDEN ET AL.

TIPPING TORCH FOR EXHAUST MACHINES Filed Feb. 21,. 19 23 ATTOR NEY reuse PATEN OFFICE.

HARRY DE FOREST MADDEN, OF NEWARK, AND JOHN JOSEPH HIGGINS, OF EAST ORANGE, NEW JERSEY, ASSIGNORS TO WESTINGHOUSE LAMP COMlPANY, A 003- rorea'rron or PENNSYLVANIA. I

EIPIQPIIQG TORCH :aoa EXHAUST MACHINES.

Application filed February 2r, 1923. Serial No. 620,348.

The present invention relates to machines for-making incandescent electric lamps and relates more particularly to a device for tippingpff the exhaust tube from an evacuated lamp bulb. v Kn object of-the present invention is to provide 'a device for the expeditions and automatic performance of a tipping off operation:

Another object of the invention is to provide a devicewhich will operate to locally heat a portion of an exhaust tube and simultaneously exert a controlledtentional stress in said heated portion to elfect a parting of a section of the exhaust tube from the exhausted bulb.

A further object of the invention is to proa device which may be automatically operated in cooperation'with an exhausting machine to effect a tipping off of an exhaust tube disposed in said machine and a removal of an evacuated lamp therefrom.

Other objects and advantages of the invention will be apparent as the description proceeds.

The manufacture of incandescent lamps includes an operation known as exhausting in whichthe bulb is evacuated toa given degree. Machines for producing a vacuum in lamp bulbs are Well known in the art, and usually include a pump and a valve con; sisting of a disc movable upon a nether plate and having suitably disposed-.ductsln given relative positions.

The ducts are connected with intermediate passages which in turn afford communication to a plurality of. ports or exhausttube receiving apertures. These tube receiving ap- 'ertures usually consist of the openings in flexible tubes of soft rubber which constitute what may be termed tube-supporting members. The disc valve may be operated to open and close the ducts leading to the supporting members to sucessively evacuate the several lamps positioned in a series of supports.

Exhausting machines of the type to which the present invention relates may consist of a conveyor preferably of circular form having a plurality of tube supporting members ad]acent the periphery thereof. The supporting members are successively connected with 'exhaust pumps for creating fronra minimum to a maximum degree of vacuum. Thus the exhaust tube of a lamp bulb being disposed in atube-supporting member is subjected to several evacuating operations until the bulb is finally evacuated to the proper degree at which time it becomes necessary to perform a tipping-off operation to seal the bulb and remove the same from. the lower portion of the exhaust tube. which remains in the supporting member after thevsealing operation.

hVhen a lamp has reached the position at which it has been sufficiently evacuated, the tipping-6ft operation is performed and it is at this point that the present invention may be applied. v

The invention therefore may operate to yieldingly secure the bulb of a lamp while fires, usually gas flames under pressure, are caused to impinge upon the'exhaust tube, at which time tensional stress is imparted to the heated portion which is subsequently severed and the bulb sealed by thecollapse of walls of the'tube.

A device for performing this operation. may comprise a bulb-carrier including a" shield and a bulb rest or rack over whichthe bulb may be positioned when the exhaust-machine has moved the bulb to a predeterminedpoint. Coordinating machine elements upon the exhausting machine and upon the tipping ofl' device may be so associated that the bulb rest will be in the properrelation to a bulb ber, produces an upward movement of the bulb-carrier with the result that the heated portion of the tube is severed and the bulb is subsequently discharged from the rack.

The invention will be more fully understood by reference to the drawings in which,

Fig. 1 is a plan view of an embodiment of the invention;

Fig. 2 is a View, partially in elevation and partially in section, of the mechanism of Fig. 1; j

Fig. 3 is a diagrammatic representation of accompanying meansfor varying the area of the passage for the outlet of the liquid.

.The invention may include a chamber or dash-pot containing any suitable liquid 6 preferably of a viscous nature. Disposed within the chamber is a weighted member or plunger 7 having its lower end immersed in the liquid. i v

The lower end of the chamber 5 may be provided with a stud 8 to which may be seured a bracket or arm 9 by means of a split collar 11. The arm 9 may, in turn, be secured to any stationary structure by tap bolts 12. v j Integral with the chamber 5 1s a radially projecting clamp 13 in which is secured an upwardly extending guide rod 14. Slidably disposed upon the guide rod 14 isa sleeve or carrier 15 which may consist of atrough shaped member having one side closed by a retainer plate 16, the plate being secured to the trough shaped portion by tap bolts 17 The upper end of the carrier may be con-- nected to one end of a chain 18 which may pass over a chain sheave 19, the other end being secured to the weighted member 7.

- The chain-sheave may be mounted on a shaft 21 journaled. in a. bearing 22 integral with a cover plate 23 which may constitute a closure for the chamber 5. A

' Secured to the upper end of the sleeve15 andofl'set therefrom, is a combined burner elementand rack which, as a whole, may be termed a bulb carrier 24, having a bulb adjuster or "steady-rest 25 suitably elevated above and fastened to burners 26 by posts 27.

The bulb carrier 24 is therefore reciprocable vertically with the sleeve 15 and may i' be partially balanced by the weighted member or counter weight 7. The counter-weight 7 is sufliciently heavier than the bulb-carrier and sleeve'so as to effect an upward movement of the carrier and sleeve due to the action of gravity upon the weight; the liquid 6 acting to retard the downward movement -of the weight. the advantage of whichwill'be more fully set forth below.

It will be understood that the bulb car-- rier and counter weight with the necessary retaining and supporting elements constitute a device which may-be applied and operated in conjunction with a lamp making machine such, formstance, as an exhausting machine. Machines for exhausting lamps are well known in the art and only such portions thereof, necessary for a complete un derstanding of the present-invention have been shown.

As illustrated in Fig. 3, a conveyor 31 of an exhausting machine is provided with a plurality of exhaust tube receiving apertures 32. The conveyor is moved in the direction of the arrow A and is provided with cam members 33 (see Fig. 4) suitably disposed upon the periphery ofthe con-' veyor; a cam being positioned adjacent each exhaust tube receiving apertures.

i The tipping-oft device may be secured by means of the bracket 9 to any suitable stationary portion of the machine in' such position that the bulb-carrier 24 overhangs the path of move-ment of'the apertures 32. A projecting roller 34 mounted on a pin 35 secured to the sleeve 15 may be positioned to engage with the cams 33 as the conveyor moves to actuate the bulb-carrier.

The conveyors of exhausting machines are generally provided with eight exhaust tube receiving apertures symmetrically spaced and adjacent to the periphery of the conveyor; the conveyor. being moved in a series of stages to successively position the apertures 32 in connection with different pumps for the exhausting operations. Thus alamp 36 may .have the exhaust tube 37'thereof disposed in an exhaust tube receiving aperture or support 32 atone stage of the movement of the conveyor and may be exhausted progressively to a given degree' v When the exhausting operation is completed one of the cams .33 will have engaged with the roller 34 and by reason of the inclination of the cam surface, the sleeve 15 will be forced downwardly with a consequent upward movement of the counter weight 7. As the conveyor continues to move, the carrier 24 being in its lower position will be so disposed that the exhausttube may enter between two sections 40 of a split shield 38 and the bulb will, by reason of the lesser diameter'at its lower end, readily enter the rack or rest 25. When the bulb is so positioned with respect to the rest, the conveyor. will have moved a sufiicient distance to permit the roller 34 to pass from the cam surface 33 thereby effecting an upward movement of the carrier until the shield 38 will have engaged with the'lower end of the bulb 36.

It will be evident that the engagement of the shield with the bulb may prevent a complete downward movement of the weighted member and that the potential energy of the weighted member may result in an upward pull upon the bulb-carrier 24 and a consequent tensional stress in the exhaust tube of the bulb. When the exhaust tube is thus stressed, the fires 26 are in position to heat the exhaust tube at itsconstricted portioa- As the material softens, the heated weakened and the stress imparted thereto effects a parting of the tube as the walls thereof collapse to close the sections of .the tube and seal the bulb.

During the heating operation, it is desirable to avoid the application of an excess amount ofhea-t to the upper portion of the exhaust tube or around the lower portion of the bulb, for which purpose the/shield 38 is provided and serves to protect the lower end of the bulb when the bulb is in the tipping-off pdsition. Sections 40 of the shield 38 may be pivoted on pins 41 mounted in a. slotted bearing block 42 which block maybe secured to the burner 26 by a stud 43. The sections 40 of the shield are normally main' tained in a closed position through the action of springs 44 secured to arms 45 integral with the bearingblock 42, and arms 46; one projecting from each section 'of the shield. The sectionsof the shield are thus resiliently held closed but the ends thereof are beveled to readilyadmit an exhaust tube and centrally disposed semi-circular notches 47 are provided to substantially fit about an exhaust tube.

The fires playing upon the exhaust tube are thus prevented from lnjurious or direct impingement upon porllons of the bulb. The fires for heating the l lb usually consist of ignited illuminating has, the gas being fed to the burner throughau inlet 48.

It is important in the tipping-off operation to gradually attenuate the he red portion of the tube and by reason oi' the liquid surrounding the lower portion of the counter weight, sudden action is prevented as the exhaust tube weakens when rendered plastic. The liquid being confined in the chamber 5 is displaced'by the weight but the rate of displacement thereof depends upon the area through which the liquid must pass to escape to the more ample or, greater capacity portion of theizhamber.

In the present invention the spaced relation ofjhe weight and the inner wall of the chamber 5 is such as to provide a constricted passage 49. Thus the opposition to the downward movement of the weight may be varied by varying the area of the passage 49. This area may be determined by experiment and fixed as shown in Fig. 2, however, when desirable, means may be provided for varying such outlet area. For this purpose, a threaded tapered collar 5.1 may be screwed on a threaded portion 52 of member 7, see Fig. 6. Thus by varying the position of collar 51 longitudinally of member 7, the outlet area 49 may be increased or decreased, thereby changing the degree of opposition afforded to the downward movement of the weight. I 7 may also be varied by varying the viscosit of the liquid 6.

The rate of movement of the weight I -veyor and so proportioned as to pass a predetermined distance above the rest 25 of the carrier 24. Therefore, when the conveyor moves, the tipping-oil device being relatively stationary, the arm 52 will engage with a lamp and eject it from the rest 25 and cause it to enter any suitable receptacle or chute for conveyance away from the machine.

It is also desirable to provide means for ejecting the surplus or waste ends of the exhaust tubes 37 from the exhaust tube apertures 32, see Fig. 3. For such purpose, the present device is provided with a projecting rod 53 which extends across and above the path of movement of the exhaust tube apertures. As the conveyor moves, the rod 53 engages'wit'h the remaining portion of the exhaust tube and tips it over and by reason of the flexible walls of the exhaust tube receiving aperture, the exhaust tube is practically wiped therefrom.

Infioperation, the lamp is placed with the exhaust tube 37 thereof in one of the apertures 32. The conveyor then moves with a series of intermittent steps during which the lamp is subjected to a plurality of evacuating operations. At the time the tube reaches the position adjacentthe tipping-off device the desired vacuum is obtained. As the conve or moves the lamp to position in operative re ation to the tipping-oil device, the roller 34 engages with the cam 33 secured to the conveyor 31. The carrier 24 is thus moved downwardly and as the conveyor comes to the proper relative position, the exhaust tube enters between the sections 40 of the split shield 38 and thelamp is positioned within the bulb-rest 25. At this point, the roller 34 moves over the end of the cam 33 and the shield 38 is moved into contact with the lower end of the bulb.

As the weight drops, its initial movement, which is c'qmparatively rapid, is retarded as a greaterwolume. of the weight enters and displaces the liquid. Since the liquid is confined to the chamber 5 and can only escape upwardly through the restricted passage 49. the downward movement of the weight will result in placing a portion of the liquid under pressure and the opposition of the liquid to the movement of the weight causes the shield 38 to move gently into contact with the lower end of a bul b thus the detrimental effect as heretofore caused by impact between the of the walls of the tube togive the desired sealing of the bulb.

lVhen the tube has been sealed off, the carrier 24 will have reached its upper position and as the conveyor'is then moved, the severed bulb is engaged by the finger 52 and is discharged from the carrier; subsequently the rod 53,engages with a portion of an ex- "haust tube of a previously tipped off bulb and as the conveyor continues to move, this tube is ejected from the aperture 32.

Heretofore devices have been constructed for performing the tipping-off operation, but

owing to certain peculiar conditions incidentto tipping-oif a lamp when being exhausted on an exhaust machine, these prior devices were unsatisfactory as they could not be made to meet the variable conditions. Furthermore, the lamp as manufactured up to the point of the tipping-off operation, may have been weakened in certain portions thereof particularly at the junction between the exhaust tube and the other component parts of the lamp. Considerable difficulty has heretofore been encountered in tippingoff a bulb without stressing, too severely, this relatively weak portion of the lamp. A certain amount of the diflieulty consisted in the lack of suitable coordinating mechanism to properly bring the shield or stop member of the lamp carrier in contact with the'end of the bulb.

In order to avoid detrimental impacts'or sudden stress, this operation must be performed in an exact and delicate manner. At the same time, a suflicient potential force must be preserved and subsequently released to to gradually impart the necessary tensional stress to the exhaust tube for the severing operation.

In the present invention the desirable cooperation of machine elements is effected whereby the shield is rapidly moved up to and makes contact with the lower end of a lamp. Severe impact, however, is avoided and at its initial stage, thestress is less than thestress subsequently applied when the exhaus t tube has been rendered plastic.

, The desirable result attained in the pres ent invention is made possible by reason of the elastic action of .the fluid 6 which maybe a medium Weight oil and in which the weight 7 is partially immersed. More positive means are thus provided for effecting the tipping-off operation. This operation is of considerable importance in the lamp industry and in order to maintain the rate of production desired of an exhaust machine it is necessary to provide a tipping torch which will operate efficiently and with a minimum amount of attention from an operator. The simplicity and positiveness 'of the "present device therefore makes it an important appliance for use with machines which operate to produce volume products such as electric incandescent lamps.

Although a preferred embodiment of the invention is shown anddescribed herewith, it is to be understood that modifications maybe made therein without departing from the spirit and scope of the appended claims.

What is claimed is: 1. A tipping ofl' device comprising a bulbcarrier, acounter weight, means for position,- ing said carrier about a bulb, means for caus ing an upward movement of said lcarrier by reason of the potentialenergy of said coun ter weight, a liquid disposed in the path of said counter Weight for displacement therebyand adjustable means-for restricting the dis- I placement of said liquid.

2. A tipping of]? device comprising a bulbcarrier,a counter weight, means for positioning said bulb-carrier about a bulb, means for" causing an upward movement of said carrier by reason of the potential energy of said' counter weight, a fluid disposed in the path of said counter weight for displacement thereby, awrestricted passage for the outlet of said fluid and means for varying thearea of said passage.

3. In a machine for exhausting electric in-' candescent lamp bulbs, the combination with a device for tipping off lamp bulbs secured in exhausting apertures of said machine,

said device comprising a bulb-carrier. a

counter weight, means associated with said machine for positioning said rest about a" bulb secured in an exhausting aperture,

means for producing a tensional stress in 

